1. Field of the Invention
The present invention relates to an adjusting mechanism for adjusting a position of an abutting member in a fastener driving device and particularly to an adjusting mechanism for adjusting the position of an abutting member used for truing up roofing materials such as asphalt roof shingles.
2. Description of the Prior Art
Generally, in a fastening operation of roofing materials such as asphalt roof shingles, the roofing materials are laid to overlap with the previously fixed roofing material in sequence and are fastened by a nail driven from a nailing machine. In this operation, it is necessary to true up the position of the roofing material to be fixed, relative to the position of the previously fixed roofing material. For this purpose, the nailing device for use with roofing materials normally includes an adjusting device for truing up the positions of the roofing materials.
Japanese laid-Open Utility Model Publication No. 57-73077 discloses an adjusting mechanism including a bolt for applying its one end on a roofing material. The bolt is mounted on a mounting plate formed with a frame of a nailing device at a position below a nail magazine. The position of one end of the bolt is adjusted by a nut engaged with the bolt.
However, with the conventional adjusting mechanism, the adjusting operation involves troublesome steps of loosening the nut, moving the bolt and thereafter tightening the nut.